The Cellular and Subcellular Bases of Immunosenescence

Thoman, Marilyn L.; Weigle, William O.

doi:10.1016/s0065-2776(08)60655-0

Cited by 315 publications

(103 citation statements)

References 228 publications

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“…Most tests of T cell function are depressed in elderly individuals (4), including even such very strong reactions as the rejection of allogeneic skin transplants in rats (5), consistent with the results in human, mentioned above. However, aside from these special cases, several studies have suggested a positive association between good T cell function in vitro and individual longevity (6)(7)(8), and between absolute lymphocyte counts and longevity (9).…”

Section: Introduction: What Is Immuno-senescence?supporting

confidence: 73%

T cells and aging (update February 1999)

Pawelec

1999

Front Biosci

113

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T cell immunosenescence 218effects of dysregulated immune responses in the elderly by supplementation or other approaches may result in an enhancement of their quality of life, and significant reductions in the cost of medical care in old age. FACTORS CONTRIBUTING TO IMMUNO-SENESCENCE HematopoiesisDysregulated hematopoiesis is seen in elderly individuals, raising the possibility that this could contribute to altered immune function in the aged. Hematopoiesis in man may be compromised because of a severely reduced capacity to produce colony stimulating factors (44) and increased production of pro-inflammatory factors such as IL 6 (45), because lower numbers of progenitor cells are present in the BM (46) and because of an age-related decline in proliferative potential of putative haematopoietic stem cells (HSC) (47). In mice, the repopulating potential of murine fetal liver-derived HSC is higher than that of adult BM-derived stem cells (48), suggesting possible aging of the HSC themselves. Normal cells with shorter telomeres possess less remaining replicative capacity than those with longer telomeres (see section 5.2). Accordingly, HSC from adult BM were found to have shorter telomeres than fetal liver-derived or umbilical cord-derived stem cells, consistent with aging of HSC (49). Telomere lengths decreased on culture despite low level expression of telomerase in these cells (50,51), although the rate of basepair loss per population doubling of cells in culture was lower during the first two weeks, when telomerase was upregulated, than in the next two, when it was downregulated (52). The telomerase expressed is therefore functionally active but may not be able to completely maintain telomere length in aging HSC cells. True embryonic stem cells (ESC), on the other hand, which may really be immortal, do retain high levels of telomerase activity (53). On the other hand, ESC from telomerase-knockout mice show gradual telomere shortening over many population doublings (PD) resulting in slowing and eventual cessation of growth (54). Certain animals which do not downregulate telomerase manifest a permanent growth phase and little or no senescence (55,56).

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Section: Introduction: What Is Immuno-senescence?supporting

confidence: 73%

T cells and aging (update February 1999)

Pawelec

1999

Front Biosci

113

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“…Macrophage production of IL-1 and TNF also changes (44). There is a depression in early signal transduction as well as a reduction in calcium fluxes (45)(46)(47)(48) in activated B and T lymphocytes in old animals. The levels of dimeric IgA produced in gut lamina propria as well as the number of CD4 + T cells in Peyers patches are significantly reduced in old animals (49,50).…”

Section: Immunoglobulin Isotypes Aging and Oral Tolerancementioning

confidence: 99%

Aging and immunoglobulin isotype patterns in oral tolerance

Faria

Ficker

Speziali

et al. 1998

Braz J Med Biol Res

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In the present review we address oral tolerance as an important biological phenomenon and discuss how it is affected by aging. Other factors such as frequency of feeding and previous digestion of the antigen also seem to influence the establishment of oral tolerance. We also analyze immunoglobulin isotypes of specific antibodies formed by tolerant and immunized animals of different ages submitted to different conditions of oral antigen administration. Isotypic patterns were studied as a parameter for assessing the pathways of B and T cell interactions leading to antibody production.

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“…Epidemiological data support beneficial effects of DHEA. Low serum DHEA levels are correlated with increased cardiovascular morbidity in men (9), breast cancer in women (10) immunocompetence during ageing (11). Data from other parts of the world indicate that, circulating levels of DHEA decrease with chronological ageing as compared to other hormones (12).…”

Section: Introductionmentioning

confidence: 99%

Serum dehydroepiandrosterone and lipid peroxides in human volunteers of different age groups

Sreeramulu

Ramalakshmi

Balakrishna

et al. 2004

Indian J Clin Biochem

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The objective of the present study was to evaluate the changes in serum dehydroepiandrosterone (DHEA) and lipid peroxide levels dudng ageing in human subjects. Random blood samples were collected from a total of 128 apparently normal human volunteers of both sexes, whose age ranged between 21-70 years. The subjects were divided into groups of a decade years of age difference.Serum levels of dehydroepiandrosterone (DHEA), lipid peroxides as malondialdehyde (MDA), and insulin were analysed in all the subjects recruited in the study. In the present study there was decrease in serum DHEA levels with age (11.30 to 7.99 ng/mi). However the differences were significant only after 50 years up to 70 years. Serum MDA levels of these subjects were higher (3.91 to 4.74 ng/ml) as compared to the values reported earlier (2.64 to 3.94 ng/ml). The serum MDA levels also showed an increasing trend with age but the increase was significant only in the 40-50 years age group and values plateaud off at later ages. The MDA and DHEA levels in women in general were lower than in men and this could be due to female hormones, which are known to protect lipid against peroxidation. There was a significant negative correlation between age and DHEA (r = -0.311 P < 0.05) and positive correction between MDA and age (r = +0.405 P < 0.01). No significant differences were seen in serum insulin, albumin and total protein levels. These preliminary findings support the possible utility of DHEA and MDA as markers for chronological ageing.

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The Cellular and Subcellular Bases of Immunosenescence

Cited by 315 publications

References 228 publications

T cells and aging (update February 1999)

T cells and aging (update February 1999)

Aging and immunoglobulin isotype patterns in oral tolerance

Serum dehydroepiandrosterone and lipid peroxides in human volunteers of different age groups

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